Commit 8658b10d authored by Tong Tiangen's avatar Tong Tiangen Committed by Wupeng Ma
Browse files

make copy_[user]_highpage_mc have return value 

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/IB0OV7



--------------------------------

There is a mechanism in the kernel to recover from uncorrectable memory
errors, ARCH_HAS_COPY_MC(eg, Machine Check Safe Memory Copy on x86), which
is already used in NVDIMM or core-mm paths(eg, CoW, khugepaged, coredump,
ksm copy), see copy_mc_to_{user,kernel}, copy_[user]_highpage_mc callers.

These two callers should return value to check whether the copy is
successful. In the current implementation, copy_[user]_highpage_mc
is not have return value.

This patch adds return value for copy_[user]_highpage_mc.

Signed-off-by: default avatarTong Tiangen <tongtiangen@huawei.com>
parent d14b2a1c

arch/arm64/include/asm/page.h

+3 −3
Original line number Diff line number Diff line
@@ -29,12 +29,12 @@ void copy_highpage(struct page *to, struct page *from); 
#define __HAVE_ARCH_COPY_HIGHPAGE



#ifdef CONFIG_ARCH_HAS_COPY_MC

extern void copy_page_mc(void *to, const void *from);

void copy_highpage_mc(struct page *to, struct page *from);

extern int copy_page_mc(void *to, const void *from);

int copy_highpage_mc(struct page *to, struct page *from);

int copy_mc_highpage(struct page *to, struct page *from);

#define __HAVE_ARCH_COPY_HIGHPAGE_MC



void copy_user_highpage_mc(struct page *to, struct page *from,

int copy_user_highpage_mc(struct page *to, struct page *from,

		unsigned long vaddr, struct vm_area_struct *vma);

#define __HAVE_ARCH_COPY_USER_HIGHPAGE_MC

#endif

arch/arm64/lib/copy_page_mc.S

+5 −1
Original line number Diff line number Diff line
@@ -74,7 +74,11 @@ CPY_MC(9998f, stnp x12, x13, [x0, #80 - 256]) 
CPY_MC(9998f, stnp	x14, x15, [x0, #96 - 256])

CPY_MC(9998f, stnp	x16, x17, [x0, #112 - 256])



9998:	ret

	mov x0, #0

	ret



9998:	mov x0, #-EFAULT

	ret



SYM_FUNC_END(copy_page_mc)

EXPORT_SYMBOL(copy_page_mc)

arch/arm64/mm/copypage.c

+15 −6
Original line number Diff line number Diff line
@@ -44,21 +44,30 @@ void copy_user_highpage(struct page *to, struct page *from, 
EXPORT_SYMBOL_GPL(copy_user_highpage);



#ifdef CONFIG_ARCH_HAS_COPY_MC

void copy_highpage_mc(struct page *to, struct page *from)

int copy_highpage_mc(struct page *to, struct page *from)

{

	void *kto = page_address(to);

	void *kfrom = page_address(from);

	int ret;



	copy_page_mc(kto, kfrom);

	ret = copy_page_mc(kto, kfrom);

	if (!ret)

		do_mte(to, from, kto, kfrom, true);



	return ret;

}

EXPORT_SYMBOL(copy_highpage_mc);



void copy_user_highpage_mc(struct page *to, struct page *from,

int copy_user_highpage_mc(struct page *to, struct page *from,

			unsigned long vaddr, struct vm_area_struct *vma)

{

	copy_highpage_mc(to, from);

	int ret;



	ret = copy_highpage_mc(to, from);

	if (!ret)

		flush_dcache_page(to);



	return ret;

}

EXPORT_SYMBOL_GPL(copy_user_highpage_mc);

include/linux/highmem.h

+11 −2
Original line number Diff line number Diff line
@@ -342,7 +342,12 @@ static inline void copy_user_highpage(struct page *to, struct page *from, 
#endif



#ifndef __HAVE_ARCH_COPY_USER_HIGHPAGE_MC

#define copy_user_highpage_mc copy_user_highpage

static inline int copy_user_highpage_mc(struct page *to, struct page *from,

	unsigned long vaddr, struct vm_area_struct *vma)

{

	copy_user_highpage(to, from, vaddr, vma);

	return 0;

}

#endif



#ifndef __HAVE_ARCH_COPY_HIGHPAGE
@@ -361,7 +366,11 @@ static inline void copy_highpage(struct page *to, struct page *from) 
#endif



#ifndef __HAVE_ARCH_COPY_HIGHPAGE_MC

#define copy_highpage_mc copy_highpage

static inline int copy_highpage_mc(struct page *to, struct page *from)

{

	copy_highpage(to, from);

	return 0;

}

#endif



#ifndef __HAVE_ARCH_COPY_HUGEPAGES

mm/memory.c

+12 −8
Original line number Diff line number Diff line
@@ -2672,10 +2672,10 @@ static inline int pte_unmap_same(struct mm_struct *mm, pmd_t *pmd, 
	return same;

}



static inline bool cow_user_page(struct page *dst, struct page *src,

static inline int cow_user_page(struct page *dst, struct page *src,

				 struct vm_fault *vmf)

{

	bool ret;

	int ret;

	void *kaddr;

	void __user *uaddr;

	bool locked = false;
@@ -2684,7 +2684,8 @@ static inline bool cow_user_page(struct page *dst, struct page *src, 
	unsigned long addr = vmf->address;



	if (likely(src)) {

		copy_user_highpage_mc(dst, src, addr, vma);

		if (copy_user_highpage_mc(dst, src, addr, vma))

			return -EHWPOISON;

		return true;

	}
@@ -2712,7 +2713,7 @@ static inline bool cow_user_page(struct page *dst, struct page *src, 
			 * and update local tlb only

			 */

			update_mmu_tlb(vma, addr, vmf->pte);

			ret = false;

			ret = -EAGAIN;

			goto pte_unlock;

		}
@@ -2737,7 +2738,7 @@ static inline bool cow_user_page(struct page *dst, struct page *src, 
		if (!likely(pte_same(*vmf->pte, vmf->orig_pte))) {

			/* The PTE changed under us, update local tlb */

			update_mmu_tlb(vma, addr, vmf->pte);

			ret = false;

			ret = -EAGAIN;

			goto pte_unlock;

		}
@@ -2756,7 +2757,7 @@ static inline bool cow_user_page(struct page *dst, struct page *src, 
		}

	}



	ret = true;

	ret = 0;



pte_unlock:

	if (locked)
@@ -2932,12 +2933,15 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf) 
		if (!new_page)

			goto oom;

	} else {

		int err;



		new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma,

				vmf->address);

		if (!new_page)

			goto oom;



		if (!cow_user_page(new_page, old_page, vmf)) {

		err = cow_user_page(new_page, old_page, vmf);

		if (!err || err == -EHWPOISON) {

			/*

			 * COW failed, if the fault was solved by other,

			 * it's fine. If not, userspace would re-fault on
@@ -2947,7 +2951,7 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf) 
			put_page(new_page);

			if (old_page)

				put_page(old_page);

			return 0;

			return err == -EHWPOISON ? VM_FAULT_HWPOISON : 0;

		}

	}